Hydraulic hoisting and rotating apparatus



Aug. 31, 1943. H. F. vlcKERs HYDRAULIC HOISTING AND ROTATING APPARATUS 1938 2 Sheets-Sheet l Original Filed March 7 INVENTOR Mime/F 140K556 Y ATTORNEYS e n! @J 0* E k n. o 0! v2 m. 60. J P w w 3. Mn 08 00 L 0! UMM 2 Sheets-Sheet ,2

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H. F. VICKERS HYDRAULIC HOISTING AND ROTATING APPARATUS Original Filed March 7, 1938 Aug. 31, 1943.

Patented Aug. 31 1943 HYDRAULIC HOISTING AND ROTATING- APPARATUS Harry F. Vickers, Detroit, Micla, assignor to Vickers, Incorporated ration of Michigan Detroit, Mich, a corpo- Orlginal application March 7, 1938, Serial No.

194,284. Divided and this application September 4, 1941, Serial No. 409,462

7 Claims.- (Cl. 121--41) This invention relates to power transmissions and more particularly to those of the fluid type wherein a power transmitting fluid, such as oil, and hereinafter referred to as such, is utilized for the transmission of power between one or more pumps and one or more fluid motors.

This application is a division of a co-pending application Serial No. 194,284, filed March '7, 1938.

It is an object of the present invention to provide a power transmission system for operating a translatable and rotatable load device, and which may be constructed as a compact unitary power device providing for smooth, yet rapid,"

translatory movement of the load device under manual control and which also provides for accurate follow-up operation of the load device to any angular position desired.

A further object is to provide a system of this character in which the rotation of the load device can be affected only when the load device has been translated to one certain position and to provide reliable, safe, and trouble-proof interlocking means for insuring this result. A, further feature of the invention resides in the provision of novel limit stop means for preventing continued rotation of the load device beyond a predetermined point by disabling the hydraulic drive mechanism and which does not,

however, prevent operation of the drive mechastructionalieatures and coordinated operation of parts as more fully set forth in the specification and claims.

Fig. 1 is a diagrammatic view of a hydraulic system embodying a preferred form of the present invention.

Fig. 2 is a longitudinal view of the follow-up valve shown diagrammatically in Fig. 1.

Fig. 3 is a, sectional view on line 33 of Fig. 2.

The embodiment of the invention selected for illustration is suitable for operating a vertically translatable head In in such a manner that the head may be either retained in its upper and inoperative position, as illustrated, or, may be moved downwardly in its lowermost position. In this latter position a rotatable member I2, which is carried. by the head In, may be rotated to any desired angular position by means of suitable follow-up control mechanism.

The power transmission system for accomplishing these movements comprises a pump l4, preferably of the variable displacement type which is mounted in an oil reservoir l8 and has a drive shaft l8 driven from an electric motor 20 by suitable drive means, such as the belt 22. The displacement of the pump l4 may be varied by means of a swinging yoke 24 pivoted at 25. In the position shown, the displacement of the pump is zero while, if the yoke 24 be swung downwardly, the displacement of the pump is increased in proportion to the amount by which the yoke is swung.

Suitable regulating means such as the cylinder 28 are provided for controlling the position of the yoke 24. The cylinder 28 contains a freely slidable piston 38, the stem 32 of which is connected by a link 34 to the yoke 24. A spring 38 norvwill be described hereafter. The extreme ends of the cylinder 28 are connected to the tank by a conduit 42.

The pump l4 withdraws oil from the tank "through a conduit 43 and delivers oil through a delivery conduit 44, having a check valve 45 for preventing return flow to the pump. The

. conduit 44 extends to a chamber 46 formed in a control block 48. The chamber 46 constitutes the main pressure chamber of a pilot operated balanced relief valve 50 which is of the same general construction as the valve disclosed in my Patent No. 2,043,453 of June 9, 1936, and'is adapted to by-pass oil to a chamber 52 whenever the oil in the control chamber 54 is vented to tank at a faster rate than it can enter the chamber 54 through the restricted orifice 58. A pilot relief valve 58 serves to thus-vent the chamber 54 to the chamber 52 through the central bore 5!] whenever the pressure in chamber 54 exceeds a predetermined safe value. A branch conduit 52 also communicates with the chamber 54 for the purpose of venting the same under certain conditions, to be later described.

The chamber 52 connects by a conduit 54 with the tank It. A conduit 56 in the valve block 58 communicates between the pressure chamber 46 and the pressure port of a four-way reverse valve 68, the tank ports or which are connected by conduits and I2 to the chamber 52. The spool 14 of the valve 68 may be moved between the position shown and a lower position by means of solenoids I6 and I8, suitable detent means 00 being provided for releasably restraining valve in either position without requiring continued energization of either solenoid. The cylinder ports of the valve 60 connect by conduits 62 and 84 with the rod and head ends of a pair of reciprocating fluid motors 86 and 08.

These motors may comprise a pair of stationary cylinders 90 and 92 in which are freely slidable a pair of differential pistons 94 and 96, hav-v ing rods 98 and I00, upon which the head I0 is supported and secured. The conduit 40 connects to the cylinder 90 at a point just below the piston 94 in its uppermost position. The pistons 96 and 06 are formed with tapered ends, as illustrated, and the conduits leading to the ends of the cylinders are provided with check valve. controlled, restricted branches, as shown, for providing a hydraulically cushioned deceleration of the pistons at either end of the stroke in the Well-known manner. The rods 96 and I00 are provided with collar-like portions I02 and I06 which may be engaged by a plurality of latch means, four of which are illustrated.

The latch means may comprise cylindrical plungers I06, having their inner ends beveled, as shown, anclnormally biased inwardly by springs I08. Each of the'plungers I06 is formed to act as a three-way valve which connects with the spring chambers when the latches are in their inward position, illustrated. When the latches are retracted outwardly, these valves are connected in a series circuit starting at the conduit IIO which is in communication with the conduit 62 at all times. A series of conduits H2, H6, II6 and H0 completes this series circuit and terminates at the operating chamber I of a pilot operated three-way valve I 22.

The valve I22 has an operating chamber I23 at its lower end containing a spring I215. The chamber I23 connects by a conduit I25 to the lower cylinder port of valve 68. The valve I22 may be provided with suitable spring detent means I26. A conduit I28 connects to the conduit 0d at a point beyond a check valve I30 and is adapted to be selectively connected by the valve I22 with either, a conduit I32 having a check valve I34 therein and communicating with the conduit 82, or a conduit I36 communicating with the lower tank port of the four-way valve 66. The conduit I36 may have a restricted portion I38 therein.

Communicating with the conduit 44 is a branch conduit I which connects to a two-way valve I02. The latter has an upwardly projecting stem I46 which may be depressed by an arm I46, carried by the head I0 when the latter descend to its lowermost position. When the valve plunger I44 is depressed, communication is established from conduit I40 to a conduit I48, leading to the pressure port of a rotary follow-up valve I50. The valve I50, which is indicated only "diagrammatically in the drawing, may be of any suitable construction whereby pressure and tank connections may be selectively reversed or shut off in accordance with the difierencein angular position between a rotary input member and a rotary follow-back or response member. of a valve of this character is illustrated in my Patent No. 2,030,902 of February 18, 1936. The tank port of the valve I50 may be connected to One example tank by a conduit I52 while th controlled ports are connected by conduits I54 and I50 with a rotary fluid motor I58. The latter may be of similar construction to the pump 24, except that .tion of the member I2.

the yoke of the motor is maintained at a fixed, though preferably adjustable, angle, at all times.

The rotary input element of the valve I50 may be connected by means, not illustrated, with a sleeve I60 which is connected by bevel gearing I62 to a handwheel I 64. The follow back or response element of the valve I50 may be connected with a shaft I66, on which the sleeve I60 is rotatably mounted. Preferably stop means I68 for limiting the relative angular displacement between sleeve I60 and shaft I66 are provided to prevent displacement of the two rotary valve controlling elements beyond the amount necessary to fully open the valve in either direction. This means may be made sufiiciently strong so as to provide a mechanical drive from the handwheel I66 to the shaft I66, should the motor I56 for any reason fail to respond to the operation of the followup valve I50.

The motor I50 has an output shaft I70 connected by a gear I12 with a gear I'M mounted for rotation in a fixed bearing, not illustrated. The gear I'M has an internally splined hub in which a splined shaft I'I6 may be slidably but non-rotatably mounted. The shaft I16 mountedin the head I0 and connects by gearing I78 to the rotatable member E2. The gear I12 at the motor I58 also connects by gearing I80 with the response shaft I66.

For the purpose .of limiting the angular rota'li tion of the rotary member I2, the gear IIl carries a gear I82 meshing with a gear I62 which connects by .bevel gearing and shafting I86 to a rotatable limit stop arm I88, mounted for rotation adjacent the valve block A8. The gear ratios are such that one revolution of the member I88 corresponds to the desired range of angular rotav The member I88 is adapted to contact a lever I00 which is connected to operate a r0tary pilot valve I92 which is normally spring centered in the positionillustrated, but which may be deflected clockwise or counterclockwise by operation of the lever I88. The valve I92 has one port I92 connected .to the conduit 62. Ports I96 and I96 are adapted to be selectively connected with the port I96 by clockwise and counter-clockwiserotation respectively of the valve I02. tank port of valve '68 by a conduit 202 and serves merely to drain any seepage of fluid from the valve I92. The ports I96 and I98 connect by conduits 204 and 206 to'the' controlled ports of follow-up valve I50, suitable check valves 20B and 2 I0 being provided in these conduits.

Suitable drain conduits 203, 205, 20?, 209 connect the spring chambers behind the latch 'plungers I06 with the tank chamber 52 in block 48. A branch 2| I also connects to the lower end of valve I42.

.The input sleeve IBI'I-for the follow-up valve may be remotely operated by a suitable Selsyn transmission system comprising a. motor 2I2 geared to the sleeve I60 and the generator 2 geared to the remote handwheel 2l6. A flywheel 2I8 may be provided at the handwheel 2I6 to limit the acceleration which may be imparted thereto. Preferably a bearing repeater is also provided at the remote control station, compris-v ing a Selsyn generator- 220 geared to the rotary member I2 and a Selsymmotor 222 operating a suitable indicating dial 224.- Signalling means.

is rotatably Port 200 is connected to the for indicating whether the head is in its hoisted or lowered position are provided which consist of a double throw switch 226, normally spring biased downwardly and adapted to be moved upwardly by a. stop 228 carried by the head I0.

'Switch 226 energized a light signal 230 when head I is up and a light signal 232 when the head I0 is down. The solenoids I6 and I8 may be controlled by suitable momentary contact push button switches 234 and 236.

For the purpose of permitting operation of the device in case of failure of electric power, a hand crank 238 may be applied to the motor shaft for operating the pump I4 manually to raise and lower th head I0. The member I2 may be rotated under these conditions by the hand crank I64 in which case a check valve 240 bypasses oil from the line 64 to the line I48 when the motor is operated in either direction and acts to pump fluid into the line I52. In case of power failure the valve spool I4 may be operated manually by the handle 242.

Inoperation, starting with the parts in the position shown in the drawing and with the motor driving the pump I4, it will be seen that so long as the valve 68 remains in its upper or hoisting position, fluid will be delivered by the pump I4 through the conduit 44, check valve 45, chamber 46, conduit 66, valve 68, conduit 84' and check valve I to the lower ends of cylinder 90 and 92. With the pistons '94 and 96 at the upper limit of their strokes, pressure will build up in cylinder 90 and being transmitted through conduit to the annular chamber 38, will move the piston 30 upwardly to approximately the position shown where the displacement of the pump is just su-ificient to make up for the total leakage in the high pressure side of the system. 7

When it is desired to lower the head I0 and rotating member l2, the switch 234 may be depressed energizing solenoid I6 to shift the spooldownwardly, connecting conduit 66 with conduit 82 and connecting conduit 84 to tank. Under these conditions pressure oil passes through conduit '82 and through the cushioning check valves to the head ends of the cylinders 90 and 92. This pressure is exerted on the inner face of the latch plungers I06 and. is sufilcient'to overcome the springs I08, withdrawing the latches from engage- -ment with the collars I02 and I04. Before the latches move outward, pressure is supplied from conduit 82 through check valve I34, conduit I32, valve I22 and conduits I 28 and 84 to the lower ends of the motor cylinders. Due to the difierential area of the. pistons the net fluid force exerted thereon is in the upward direction, tending to relieve the gravity load on the latches I06 and thus making their outward movementfree from frictional drag caused by the weight of the head I0 and associated parts. i

As soon as all of the latches I06 have moved outwardly, pressure oil is transmitted through theseries circuit at the latch valves through conduits H0, H2, H4, '6 and H8 to the upper operating chamber I20 of the valve I22. The latter. shifts downwardly discharging oil from the lower chamber I 24 through conduit I25 to the tank. With the valve I22 in its lower position, conduit I32 is cut off from conduit I28 and the latter is connected to tank through conduit I36, restrictor I38, valve 68, conduit I2, chamber 62 and conduit '64. The pistons 94 and 96 accordingly descend due to the combined weight of the head I0, and the fluid pressure on top of the pistons,

the rate of descent being slowed down somewhat by the restrictor I38.

subject to high pressure and the piston 30 accordingly moves downwardly to bring the pump into full displacement position. As soon as the piston 94 passes the conduit 40, the latter is again connected to the discharge side of the pump and the pump regulates itself to maintain a constant delivery pressure. As the pistons 94-and 96 approach the end of their stroke, they are decel erated by the cushioning chambers, pressure remaining on top of the pistons to hold the head I0 4 i in its downward position. With the pistons thus stalled at the bottom of the cylinders, the pump displacement regulator again swings the yoke 24 to approximately neutral position. v

As the head I0 reaches the bottom of its stroke, arm I46 depresses plunger I 44 of valve I 42 thus connecting conduit I48 to the delivery conduit 44 of the pump. The system is now ready for operation of the rotating element I2 under the control of the follow-up valve I50. Thus if the handwheel 2 I 6 be rotated to any new position this motion is transmitted through the Selsyn system 2I2-2I4 to the sleeve I60, which controls the input member of the follow-up valve I50. The relative displacement between the input member and the response member thus produced, opens the valve I 50 to flow of oil from conduit I48 to whichever of the conduits I54 or I56 will cause rotation of the motor I58 in a correspondin direction. The discharge from the motor returns from the follow-up valve I50 through conduits I52 and 64 to the tank. The unit I2 may thus be rotated to any desired position, at will, by operation of the handwheel 2 I 6. The bearing repeater 224 of course indicates all movements of the member I2.

If the member I2 be rotated too far in a given direction, the limit stop arm I 88 is caused to abut the pilot valve lever I90 and opens communication between port I94 and either port I96 or I98 depending upon the direction in which the arm I88 approaches the lever I90. Assume, for example, that the handwheel 2I6 is turned in the direction causing the follow-up valve I50 to admit pressure oil to the conduit I 54 and thus causing the shaft I10 to rotate in the direction of the arrow. The direction of rotation of the other shaftswill be as indicated by the arrows, thus moving the lever I90 clockwise and connecting port I94 to port I96. The control chamber 54 of the relief valve 50 is thus vented to tank through conduit 62, port I94, valve I92, port I96, conduit 204, check valve 208, follow-up valve I50 and conduits I52 and 64. Oil discharged by the pump is thus by-passed at the valve 50 from chamber 46 to chamber 52 and through conduit 64 to the tank, thus preventing further operation of the motor I58 in that direction.

If now the handwheel 2I6 be turned in the opposite direction so as to move the follow-up valve to connect conduit I 56 to the pressure contermined by the arm I88, the operation is similar to that described except that all shafts turned in the direction opposite to the "arrows and the relief valve is vented-through conduit 206, instead of conduit 204. Here again, as soon as the follow-up valve operates to back up from the limiting-position, pressure builds up behind the check valve 2Ill and the relief valve is no longer vented.

When it is desired to raise the head I2, switch 236 is closed, energizing solenoid I8 and lifting the valve spool 14 again to the position shown in the drawings. The rod ends of the cylinders 90 and 92 are now connected to tank through conduit 82, conduits I0, I2 and 64. Pressure oil from the chamber 46 is admitted to the conduit I and chamber I24 to shift the valve I22 upwardly, discharging oil from the chamber I20 throu h conduit N8, the three-way valve at the right hand latch plunger I06 and the drain conduit 209 to tank. It will be noted that due to the tank 9 pressure existing in the upper 'ends of cylinders 90 and 92, that the springs I08 move all the latch plungers I06 inwardly. Pressure oil is also delivered from the conduit 66 through conduit 84 and check valve I to the lower ends of the cylfinders 90 and 92, thus moving the pistons and the head Ill upwardly until the position, shown 2. In a fluid power transmission system the combination with means forming a source of fluid under pressure, a reversible motor operable on fluid supplied from said source, follow-up means for controlling the supply of fluid to the motor to effect movement thereof selectively to.

predetermined positions, means for interrupting the supply of fluid to the motor and a pilot circuit controlling the interrupting means and including a valveactuated upon a predetermined amount of movement of themotor in either direction, said pilot circuit being connected through the follow-up control means to nullify the operation of the interrupting means on operation of the follow-up control means to cause movement of the motor in a direction reverse to that from which it was stopped by the interrupting means.

3. In a fluid power transmission system of the combination with means forming a source of fluid under pressure, of a motor operable on fluid supplied from said source, follow-up means having ports which are alternately pressure or exhaust depending on the direction of movement for controlling the supply of fluid to the motor to effect movement thereof selectively to v predetermined positions, limit stop means for inin the drawings, is reached. The latch plungers I 6 then engage-the collars I02 and I04 and since the piston 94 is now above the conduit 40, the pump 24 is again regulated to its small displacement position sufficient to maintain the desired pressurebeneath the pistons 94 and 96.

If for any reason the supply of electric power should be interrupted, the pump l4 may be operated by the hand crank 238 to lower the head I0 in a similar manner to that previously described. The valve spool 14 maybe operated manually by the handle 242 for this purpose.

When the head I0 has descended check valve 45 prevents upward movement thereof, this valve also serving to prevent falling of the head I0 while it is being hoisted by the operation of the hand crank 238. When the head is in its lowered position the same may be rotated manually by the operation of the handwheel I64 which, by means of the stop mechanism I68, provides a direct mechanical drive to the rotatable member I2. The motor I58 is, of course, mechanicallydriven during such operation and oil discharged into the tank conduit I52 may return to the opposite side of the motor I58, through conduit 64 and check valve 240. The flow is always in the same direction regardless of the direction of operation of hand wheel I64 since the follow-up valve I50 reverses connectionsto the motor I58 each time the hand wheel is reversed.

What is claimed is as follows:

1. In a fluid power transmission system the combination with means forming a source of fluid under pressure, a reversible motor operable on fluid supplied from said source, follow-up means for controlling the supply of fluid to the motor to effect movement thereof selectively to predetermined positions, limit stop means for interrupting the supply of fluid to the motor when the motor has moved a predetermined amount in either direction and the follow-up control means is operated to continue such movement, and

a means connecting the limit stop .means to the follow-up control means to cause reverse operation of the motor upon reverse operation of the follow-up control means while the limit stop means is still eflective.

terrupting the supply of fluid to the motor when the motor has moved a predetermined amount in one direction and the follow-up control means is operated to continue such movement, and means hydraulically connecting the limit stop means to pressure-exhaust ports in said follow-up control means to cause. reverse operation of said control upon reverse operation of the follow-up control means while the limit stop is effective.

4. In a. fluid power transmission system of the combination with means forming a source of fluid under pressure, of a motor operable on fluid supplied from said source, follow-up means having ports which are alternately pressure or exhaust depending on the direction of operation for controlling the. supply of fluid to the motor to efiect movement thereof selectively to predetermined positions, limit stop means for interrupt ing the supply of fluid to the motor, and a pilot circuit controlling the interrupting means and including a valve actuated upon a predetermined amount of movement of the motor in one direction, conduits between said valve and pressureexhaust ports of said follow-up means, said follow-up means beingefiective to connect one of said conduits to the tank, and check valves in said conduits to permit reverse of said follow-up means while said limit-stop means is effective.

5. In a fluid'power transmission system the I combination with means forming a source of for said bypass valve including a pilot circuit con;

fluid under pressure of a motor'operable on fluid operated from said source, follow-up means having ports to act alternately as pressure or exhaust ports depending on the directionof operation thereof and for controlling the s'upplyof fluid of the motor to effect movement thereof selectively to predetermined positions, a bypass valve for bypassing fluid delivered from the source, and-a-pilot controlled operating means I necting to the operating means of the bypass valve and including a limit valve, first and second lines connecting pressure-exhaust ports of said follow-up device with said limit valve and normally blocked by said limit valve, means operably connecting said motor and said limit valve to open the same upon predetermined movement of said motor whereby said pilot circuit will be the interrupting means low-up control means to cause movement of the motor-in a direction reverse to'that from which valve, and means in said lines to permit reverse operation of said motor by blocking the line then connected to exhaust while said limit valve is (still open.

c'uit controlling the interrupting means including a valve actuated upon a predetermined amount of movement'of the motor in either direction, said low-up control means to nullify the operation of on operation or the 1'01- it was stopped by interrupting means, and means returning said valve to original position upon slight reverse operation of the motor to reset the pilot circuittor further interrupting means and operation;

. pilot circuit being connected through the folreverse operation of the eration of the follow-up control means while the 7. In a fluid-power transmission system the combination with means forming a source of fluid under pressure, a reversible motoroperable on fluid supplied from said source, follow-up means for controlling the supply of fluid to the motor to efiect movement thereof selectively to predetermined positions, limit stop means for.

interrupting the supply of fluid to the motor when the motor has moved a predetermined amount in either direction and the follow-up control means is operated to continue such movement, said limit stop means comprising a spring centered venting valve, and a pressure biased bypas 'vaive connected to the source and responsive to movement of said venting valve away from center, and means connecting the limit stop means to the follow-up control means to cause limit stop me centered valve ns-is still eflective, said spring returning to center upon slight reverse operation of the motor.

v HARRY F. VICKERS.

motor upon reverse op- 

